Medical/biological study (experimental study)

Whole-body exposure of radiation emitted from 900 MHz mobile phones does not seem to affect the levels of anti-apoptotic bcl-2 protein med./bio.

By: Yilmaz F, Dasdag S, Akdag Z, Kilinc N

Published in: Electromagn Biol Med 2008; 27 (1): 65-72

Aim of study (acc. to author)

To investigate the anti-apoptotic bcl-2 protein in rat brain and testes after whole body exposure to irradiation emitted from 900 MHz cellular phones.

Background/further details

16 male rats were separated into a control and an experimental group. For the experimental group the phones transmitted speech for 20 minutes per day for one month.

Endpoint

cell viability/cell division/proliferation: apoptosis

Exposure

- mobile communications
- digital mobile phone
- GSM

Exposure	Parameters
Exposure 1: 900 MHz Modulation type: pulsed Exposure duration: repeated daily exposure, 20 min/day, for 1 month	power: 2 W peak value power: 250 mW mean electric field strength: 13.59 V/m mean power density: 0.047 mW/cm² mean SAR: 3.13 W/kg effective value (1 g) SAR: 0.52 W/kg effective value (whole body) (0.29- 0.87 W/kg)

Exposure 1

Main characteristics

Frequency	900 MHz
Type	electromagnetic field
Exposure duration	repeated daily exposure, 20 min/day, for 1 month

Modulation

Modulation type	pulsed
Additional info	The mobile phones transmitted human speech from a tape to the base station.

Exposure setup

Exposure source	cellular phone GSM
Distance between exposed object and exposure source	5 mm
Chamber	The rats were confined in Plexiglas cages (20 cm x 10.5 cm x 10 cm) with ventilation holes, and the mobile phones were placed under the cages.
Setup	Exposure began when the rats settled down to a prone position and selected a fixed location inside the cage spontaneously.
Sham exposure	A sham exposure was conducted.
Additional info	The same phones were placed under the control rats but they were turned off.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power	2 W	peak value	-	-	-
power	250 mW	mean	-	-	-
electric field strength	13.59 V/m	mean	measured	-	-
power density	0.047 mW/cm²	mean	measured	-	-
SAR	3.13 W/kg	effective value	calculated	1 g	-
SAR	0.52 W/kg	effective value	measured and calculated	whole body	0.29- 0.87 W/kg

Additional parameter details

Taking into account the very simple shape of the model used in the simulation, the SAR values are approximate. In addition, due to the adaptive power control of the base station, the radiated power was variable during the study. Minimum and maximum SAR levels were also measured.

Measurement and calculation details

Average field strength and power density were measured using a radiation meter. For checking the availability of the signal, cell sensor equipment was used having a sensitivity of 0-10 mW/cm². The FDTD method was used to calculate SAR. The simulation was performed using Finite Integration Technique (FIT) which in the time domain case is similar to FDTD. The FCC recommended parameters for average muscle dielectric constant and conductivity at 900 MHz were used to simulate the rat model which was an ellipsoid with 100 and 28 mm semi axis. The phone model was a metallic box of 90 x 40 x 15 mm mounted with a monopole antenna of 80 mm. Distance between the rat model and the phone model was 5 mm.

Exposed system:

Methods Endpoint/measurement parameters/methodology

cell viability/cell division/proliferation: apoptosis (expression of anti-apoptotic bcl-2 protein; immunohistochemistry)

Investigated system:

tissue slices

Investigated organ system:

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The results showed that 20 minutes of the irradiation emitted from 900 MHz cellular phones did not alter anti-apoptotic bcl-2 protein in the brain and testes of rats.
It was concluded that bcl-2 may not be involved in the effects of irradiation on the brain and testes of rats.

Study character:

medical/biological study
experimental study
pilot/exploratory/preliminary study

Study funded by

not stated/no funding

Ait-Aissa S et al. (2010): In situ detection of gliosis and apoptosis in the brains of young rats exposed in utero to a Wi-Fi signal
Moquet J et al. (2008): Exposure to low level GSM 935 MHZ radiofrequency fields does not induce apoptosis in proliferating or differentiated murine neuroblastoma cells
Dasdag S et al. (2008): Mobile phone exposure does not induce apoptosis on spermatogenesis in rats
Kim TH et al. (2008): Local exposure of 849 MHz and 1763 MHz radiofrequency radiation to mouse heads does not induce cell death or cell proliferation in brain
Joubert V et al. (2007): No apoptosis is induced in rat cortical neurons exposed to GSM phone fields
Zhao TY et al. (2007): Exposure to cell phone radiation up-regulates apoptosis genes in primary cultures of neurons and astrocytes
Marinelli F et al. (2004): Exposure to 900 MHz electromagnetic field induces an unbalance between pro-apoptotic and pro-survival signals in T-lymphoblastoid leukemia CCRF-CEM cells
Dasdag S et al. (2004): Does 900 MHz GSM Mobile Phone Exposure Affect Rat Brain?
Dasdag S et al. (2003): Whole body exposure of rats to microwaves emitted from a cell phone does not affect the testes